Evaluating the Ergonomics of Healthcare Providers using Kinematic Motion Analysis, Electromyography, and Musculoskeletal Modeling

Title from PDF of title page viewed May 10, 2019Dissertation advisor: Gregory W. KingVitaIncludes bibliographical references (pages 107-118)Thesis (Ph.D.)--School of Computing and Engineering and School of Medicine. University of Missouri--Kansas City, 2018Work-related musculoskeletal disorders (MSDs) in healthcare providers have been heavily reported, and are a major cause of occupational discomfort, disability, and occupational absence. Current evaluation methodology of occupational posture in healthcare professionals includes qualitative methods such as survey-based instruments that report on the characteristics of existing pain, or observational instruments where still photographs or videos of occupational postures are evaluated by independent raters to assess risk or exposure to musculoskeletal disorders. This research program used marker-based kinematic motion capture, surface electromyography, and musculoskeletal modeling to evaluate occupational postures in eye care providers and dental operators. Reclining the patient during refraction and strabismus exams reduced the amount of procedural time that eye care providers’ necks were in non-neutral postures. For eye care providers performing the slit lamp exam, it was observed that moving the patient forward and adjusting slit lamp biomicroscope height led to reduced non-neutral neck postures as indicated by a reduction in sagittal plane neck flexion range of motion, upper trapezius muscle activity and the percentage of procedural time with non-neutral neck flexion. Additionally, the use of an elbow rest when holding up exam lenses at the slit lamp reduced the procedural time that the anterior deltoid muscle was active, indicating a lower likelihood of shoulder musculoskeletal disorders. For dental operators, this research investigated the effect of using two kinds of Galilean magnification loupes on neck postures in dental hygienists performing sub-gingival probing. It was observed that both loupes reduced the range of motion of sagittal plane neck flexion in dental hygienists when compared to no magnification. The use of two kinds of through-the-lens Galilean loupes used by ophthalmic surgeons was also evaluated using motion capture, electromyography, and musculoskeletal modeling. A musculoskeletal model of a 50th percentile adult male demonstrated that holding a human head balanced at the working neck flexion of a lighter loupe required a smaller angular torque than a heavier loupe. Since this lower torque was a function of both neck flexion and loupe weight, neck muscle activity was evaluated at three different neck flexions for both loupes. It was observed that using a lighter loupe with a larger angle of declination led to a decrease in upper trapezius muscle activity. Postural adjustment, patient positioning, equipment re-positioning and supportive equipment choice (such as elbow rests for slit lamp examinations, or magnification loupes for periodontal probing and ophthalmic surgery) may be easy to implement methods that can reduce the exposure of healthcare providers to work-related musculoskeletal disorders.Introduction -- Background -- Evaluating posture in eye care providers performing refraction and strabismus exams using kinematic motion capture and electromyography -- Postural evaluation of eye care providers at the Slit Lamp using kinematic motion capture and electromyography -- Using motion capture technology to measure the effects of magnification loupes on dental operator posture: a pilot study -- Effect of magnification loupe weight and angle of declination on neck muscle effort in ophthalmic surgeons -- Conclusion -- Appendice

Evaluating the Ergonomics of Healthcare Providers using Kinematic Motion Analysis, Electromyography, and Musculoskeletal Modeling

Title from PDF of title page viewed May 10, 2019Dissertation advisor: Gregory W. KingVitaIncludes bibliographical references (pages 107-118)Thesis (Ph.D.)--School of Computing and Engineering and School of Medicine. University of Missouri--Kansas City, 2018Work-related musculoskeletal disorders (MSDs) in healthcare providers have been heavily reported, and are a major cause of occupational discomfort, disability, and occupational absence. Current evaluation methodology of occupational posture in healthcare professionals includes qualitative methods such as survey-based instruments that report on the characteristics of existing pain, or observational instruments where still photographs or videos of occupational postures are evaluated by independent raters to assess risk or exposure to musculoskeletal disorders. This research program used marker-based kinematic motion capture, surface electromyography, and musculoskeletal modeling to evaluate occupational postures in eye care providers and dental operators. Reclining the patient during refraction and strabismus exams reduced the amount of procedural time that eye care providers’ necks were in non-neutral postures. For eye care providers performing the slit lamp exam, it was observed that moving the patient forward and adjusting slit lamp biomicroscope height led to reduced non-neutral neck postures as indicated by a reduction in sagittal plane neck flexion range of motion, upper trapezius muscle activity and the percentage of procedural time with non-neutral neck flexion. Additionally, the use of an elbow rest when holding up exam lenses at the slit lamp reduced the procedural time that the anterior deltoid muscle was active, indicating a lower likelihood of shoulder musculoskeletal disorders. For dental operators, this research investigated the effect of using two kinds of Galilean magnification loupes on neck postures in dental hygienists performing sub-gingival probing. It was observed that both loupes reduced the range of motion of sagittal plane neck flexion in dental hygienists when compared to no magnification. The use of two kinds of through-the-lens Galilean loupes used by ophthalmic surgeons was also evaluated using motion capture, electromyography, and musculoskeletal modeling. A musculoskeletal model of a 50th percentile adult male demonstrated that holding a human head balanced at the working neck flexion of a lighter loupe required a smaller angular torque than a heavier loupe. Since this lower torque was a function of both neck flexion and loupe weight, neck muscle activity was evaluated at three different neck flexions for both loupes. It was observed that using a lighter loupe with a larger angle of declination led to a decrease in upper trapezius muscle activity. Postural adjustment, patient positioning, equipment re-positioning and supportive equipment choice (such as elbow rests for slit lamp examinations, or magnification loupes for periodontal probing and ophthalmic surgery) may be easy to implement methods that can reduce the exposure of healthcare providers to work-related musculoskeletal disorders.Introduction -- Background -- Evaluating posture in eye care providers performing refraction and strabismus exams using kinematic motion capture and electromyography -- Postural evaluation of eye care providers at the Slit Lamp using kinematic motion capture and electromyography -- Using motion capture technology to measure the effects of magnification loupes on dental operator posture: a pilot study -- Effect of magnification loupe weight and angle of declination on neck muscle effort in ophthalmic surgeons -- Conclusion -- Appendice

Use of Biomechanical Motion Analysis to Evaluate Endotracheal Intubation Skill in a Simulated Clinical Setting

Title from PDF of title page, viewed on August 25, 2015Thesis advisor: Gregory W. KingVitaIncludes bibliographic references (pages 102-107)Thesis (M.S.)--School of Computing and Engineering. University of Missouri--Kansas City, 2015This study evaluated, using motion capture technology, the performance characteristics of novice and experienced medical personnel performing endotracheal intubation in a simulated clinical setting. Few objective measures exist that quantify the differences in intubation techniques between providers of various skill levels. These measures are inadequate for providing useful feedback towards training or performance-based research. Motion analysis may be a potential solution for the quantitative evaluation of endotracheal intubation among healthcare professionals of different skill levels. This study hypothesized that experienced personnel would exhibit movement patterns associated with higher performance and efficiency when compared to novice personnel. Twelve subjects were recruited for this study, among whom eight were novice participants and four were expert participants, based on the number of times they had performed endotracheal intubation. Each subject donned a full body 41 marker motion capture suit and performed simulated endotracheal intubation on an Airway mannequin using a Macintosh blade-fitted laryngoscope. Intubation success was defined by visible lung inflation of the mannequin. The obtained motion capture data was used to calculate path length, average path speed and use time of the laryngoscope, as well as the overall intubation time. Angular ranges of motion were calculated for the left wrist, elbow, the neck, and both knees of study subjects. Experts, when compared to novices, intubate faster and with lower overall movement (path length). One way ANOVA and two sample t-tests were conducted on all outcome variables, wherein significant p-values were obtained from the wrist abduction/adduction (p = 0.009) and elbow abduction/adduction (p=0.002) ranges of motion among novices and experts, indicating significant difference. Combined with a lower completion time and the lower overall laryngoscope movement, the lower range of motion for the wrist and the elbow in experts may indicate that experts are implementing finer, more economic maneuvers in order to achieve successful intubation. These results supports the study hypothesis that experienced personnel, compared to novice, will exhibit measurable movement patterns associated with higher performance and efficiency.Introduction -- Background -- Study -- Conclusion -- Appendix A. Equipment photographs, layout schematics, study illustrations -- Appendix B. Tables -- Appendix C. MATLAB Code -- Appendix D. Study forms and document

Challenges in Kinetic-Kinematic Driven Musculoskeletal Subject-Specific Infant Modeling

Musculoskeletal computational models provide a non-invasive approach to investigate human movement biomechanics. These models could be particularly useful for pediatric applications where in vivo and in vitro biomechanical parameters are difficult or impossible to examine using physical experiments alone. The objective was to develop a novel musculoskeletal subject-specific infant model to investigate hip joint biomechanics during cyclic leg movements. Experimental motion-capture marker data of a supine-lying 2-month-old infant were placed on a generic GAIT 2392 OpenSim model. After scaling the model using body segment anthropometric measurements and joint center locations, inverse kinematics and dynamics were used to estimate hip ranges of motion and moments. For the left hip, a maximum moment of 0.975 Nm and a minimum joint moment of 0.031 Nm were estimated at 34.6° and 65.5° of flexion, respectively. For the right hip, a maximum moment of 0.906 Nm and a minimum joint moment of 0.265 Nm were estimated at 23.4° and 66.5° of flexion, respectively. Results showed agreement with reported values from the literature. Further model refinements and validations are needed to develop and establish a normative infant dataset, which will be particularly important when investigating the movement of infants with pathologies such as developmental dysplasia of the hip. This research represents the first step in the longitudinal development of a model that will critically contribute to our understanding of infant growth and development during the first year of life

Hip Mechanics of Infants: Understanding Hip Angles of an Infant in Different Baby Carrier Styles

Infant position in baby carriers can affect their hip development and health. The Pavlik Harness is a device used to treat Developmental Dysplasia of the Hip (DDH) and is the standard for the healthy hip position of 90° flexion and 80° abduction angles. Standardized baby carrier styles that promote healthy hip position have not yet been established. The purpose of this study was to develop testing methods to accurately measure infant hip angles in various baby carriers. Three baby carriers under four conditions were placed on an adult manikin. One manikin representing a newborn which weighed approximately 2.83 kilograms was placed under the four conditions. The hip flexion and abduction angles were measured using a goniometer. The flexion angles were calculated through a MATLAB photo analysis function. The maximum force, peak pressure, and mean pressure that the carrier exerted onto the infant were measured during the first trial using two Novel pressure sensors. The sensors were placed around one thigh and the back and gluteus maximus. The Novel data was inconsistent and unreliable to measure forces exerted on the infant. Carrier B’s data resulted in the most similar hip position to the Pavlik Harness positioning. Carrier C’s data proved that it does not support the infant’s hips for healthy positioning. 75% of the photo analysis method resulted in smaller flexion angles compared to the measured angles using the goniometer. Labeling the anatomical landmarks for the photo analysis method was accessible and consistent. It was difficult to measure angles with the goniometer due to its shape and the positioning of the infant in the baby carrier. This preliminary data collection will lead to more advanced and detailed research with human subjects. A possible method for measuring hip flexion and abduction more accurately is to imbed a digital goniometer into the infant manikin or use a marker-based motion capture system like VICON. A standard for new baby carrier designs will be created when the optimal baby carrier style for hip position is identified

Muscles & Motion: Understanding the Muscle Utilization of How Babies Achieve a Roll

Achieving a roll is a key motor skill and an important developmental milestone for babies. To initiate and complete a roll, babies must use whole-body, goal-oriented movements that take them from their back to their stomach. Previous research about baby biomechanics, particularly in rolling, is sparse. Only one previous study has established six different coordinated movements that a baby may use to achieve a roll. However, no studies have explored how these coordinated movements are related to muscle activation. The purpose of this study is to develop a quantifiable method characterizing muscle activation and coordinated movements of infant rolling. Twenty-four healthy babies (14M, 10F, 6.7 ± 0.7 months) participated in this IRB-approved study, where seventy-two half rolls were analyzed. Analysis was done with electromyography (EMG) sensors that records muscle activity. A GoPro camera allowed us to visually determine which movement type a baby is using to achieve a roll while the EMG sensor data shows the corresponding muscle activation. These results indicate a promising approach towards quantifying the movement patterns of roll initiation using a combination of video and EMG analysis. Understanding how babies achieve a roll on a flat surface is crucial in determining key product design features needed to keep babies safe. This could lead to improved regulations for infant safety when creating new products

Identifying Strategies Used to Negotiate Stairs When Carrying an Infant Surrogate

For the first year of life, humans depend on caregivers to transport them. While carrying infants in arms, wraps, or carriers on a parent’s body have been used for centuries, modern infant product design has introduced alternative methods to carry infants including car seats and strollers. However, it is unclear how these different carrying methods may impact a caregiver’s biomechanics or risks of injury. The objective of this study is to identify strategies used when negotiating stairs with a 12 pound infant manikin. An outdoor obstacle course was designed, representing typical activities required to navigate urban architecture: ascending and descending stairs and ramps, entering and exiting buildings, and crossing curbs. The course was completed by ten healthy female participants (aged 21-24 years). A pre-testing questionnaire was completed by each participant to screen out potential participants who were mothers or who had current injuries and/or pain. All participants were injury and pain free. No participant was a mother or had been previously pregnant. Participants carried an infant manikin in a carrier, car seat, stroller, and in arms through the urban obstacle course. Each carrying method was completed six times, three times forward and three times backwards through the course. High-speed video cameras filmed each obstacle along the course. This abstract focuses only on the stair obstacle. Three investigators watched fifty randomly selected trials and identified them. A total of 240 trials were collected. Six trials had to be excluded due to equipment malfunctions. The breakdown of device conditions of the remaining 234 trials were 59 in arms, 59 in a carrier, 60 in a car seat, and 56 in a stroller. Investigators watched 50 random trials and denoted movement strategies for each carrying condition based on defining characteristics. When carrying the infant manikin in arms four main strategies were observed; carrying on the hip with a single arm (dominant or non-dominant) with and without support from the second arm. When walking with the manikin in a baby carrier three main strategies were observed: arms hanging freely, arms wrapped around the carrier providing additional support, and arms resting on the carrier providing little to no support. Six strategies were identified in the car seat condition: carrying the car seat at the elbow (dominant and nondominant) with and without support from the second arm (support), a mixed grip, and a single arm “lock” grip. Five strategies were identified in the stroller condition: a forward push, a backwards pull, a front wheel pop, carrying, and a step by step carry. A “switch” and an “other” category were added to each condition for cases when a participant transferred between strategies or used a strategy not defined above. The most commonly employed strategy across all conditions was free hanging arms when the manikin was in a carrier. Free arms were seen in 45.8% of trials in the carrier condition. In the in arms condition the single arm (dominant) + support was the most commonly employed strategy accounting for 44.1% of all in arms trials. The most common strategy for carrying the car seat was carrying at the elbow (dominant) + support, which was observed in 25% of the car seat trials. Carrying the stroller was the most common strategy implemented in the stroller condition, and accounted for 35.7% of stroller trials. There was more variability in the strategies chosen for the car seat and stroller conditions than the in arms or carrier conditions during stair negotiation. This may be attributed to a relative lack of infant care experience in the participants. The car seat and stroller were also the bulkiest carrying devices which may have increased carrying difficulty. This may have contributed to participants changing between carrying strategies across trials and within trials. Greater consistency may be seen in future studies conducted on mothers and other primary caregivers of infants

Navigating the Concrete Jungle: Feasibility of Quantifying the Biomechanics of Parents Carrying Infants in a Non-Laboratory Setting

For the first year of life, human babies depend on their caregivers to transport them. While carrying infants in arms and in wraps/carriers on a parent’s body have been used for centuries, modern infant product design has introduced alternative methods to carry infants including car seats and strollers. However, it is unclear how these different carrying methods may impact a caregiver’s biomechanics or risks of injury. The objective of this pilot study is to assess the feasibility of collecting biomechanical data on caregivers carrying infants in real world scenarios. An obstacle course was designed outside the lab representing realistic daily activities: walking, descending/ascending stairs and ramps, and opening/navigating doors. Each obstacle was completed by a female participant with an infant manikin in four carrying positions: held in arms, secured in a car seat, held in a baby carrier on the participant’s body, and secured in a stroller. Electromyography (EMG) and inertial measurement unit (IMU) sensors were placed on key muscles and body segments to measure muscle activity and movement. We successfully collected data throughout the designed obstacle course, and the results show characteristics distinct to each mode of movement. Future work involves additional activities and 20+ participants

Challenges in Kinetic-Kinematic Driven Musculoskeletal Subject-Specific Infant Modeling

Musculoskeletal computational models provide a non-invasive approach to investigate human movement biomechanics. These models could be particularly useful for pediatric applications where in vivo and in vitro biomechanical parameters are difficult or impossible to examine using physical experiments alone. The objective was to develop a novel musculoskeletal subject-specific infant model to investigate hip joint biomechanics during cyclic leg movements. Experimental motion-capture marker data of a supine-lying 2-month-old infant were placed on a generic GAIT 2392 OpenSim model. After scaling the model using body segment anthropometric measurements and joint center locations, inverse kinematics and dynamics were used to estimate hip ranges of motion and moments. For the left hip, a maximum moment of 0.975 Nm and a minimum joint moment of 0.031 Nm were estimated at 34.6° and 65.5° of flexion, respectively. For the right hip, a maximum moment of 0.906 Nm and a minimum joint moment of 0.265 Nm were estimated at 23.4° and 66.5° of flexion, respectively. Results showed agreement with reported values from the literature. Further model refinements and validations are needed to develop and establish a normative infant dataset, which will be particularly important when investigating the movement of infants with pathologies such as developmental dysplasia of the hip. This research represents the first step in the longitudinal development of a model that will critically contribute to our understanding of infant growth and development during the first year of life

How Do Babies Roll?: Understanding How Babies 3-7 Months Achieve a Roll

Achieving a roll is a key motor skill and an important developmental milestone for babies. To initiate and complete a roll, babies must use whole-body, goal-oriented movements that take them from their back to their stomach. Previous research about baby biomechanics, particularly in rolling, is sparse. Only one previous study has established six different coordinated movements that a baby may use to achieve a roll. However, no studies have explored how these coordinated movements are related to muscle activation. The purpose of this study is to determine which muscles are used during various movements of babies rolling from their back to their stomach. Five healthy babies (4M, 1F, 6.7 ± 0.8 months) participated in this ongoing IRB-approved study, where eight half rolls were analyzed. Analysis was done with a motion capture system that tracks their movements using reflective markers and specialized cameras. Electromyography (EMG) sensors that records muscle activity were also used. The motion capture data collected allows us to visually determine which movement type a baby is using to achieve a roll while the EMG sensor data shows the corresponding muscle activation. The preliminary results indicate a promising approach towards quantifying the movement patterns of roll initiation using a combination of motion capture and EMG analysis. Understanding how babies achieve a roll, will help us determine how rolling changes as a healthy baby ages. A rolling standard can then be developed that shows when a baby’s rolling is not progressing as expected, indicating other developmental concerns